This invention relates to weighted capacitor analog/digital conversion circuitry and techniques and more particularly to such conversion techniques utilizing metal oxide semiconductor circuitry providing conversion with either a linear relationship between the analog and digital signals or a nonlinear relationship therebetween.
Conventional techniques for performing analog/digital conversion generally require sophisticated analog circuitry including operational amplifiers, and digital circuitry for counting, sequencing, and data storage. Consequently, hybrid circuits have resulted including one or more bipolar analog circuit elements together with metal oxide semiconductor circuit elements for performance of the digital functions while remaining within reasonable economic limits. Applications exist for coding analog signals in nonlinear digital codes and for subsequent decoding to an analog form. Voice signals for telephone transmission and subsequent reception are often subjected to such nonlinear coding and decoding. Present coder/decoder installations are complex and expensive, therefore requiring multiplexing for sharing of the installations so that they may accommodate multiple telephone transmissions simultaneously. A low cost configuration of minimal complexity is desirable for use in both linear and nonlinear conversion between analog and digital signal forms, while maintaining low error and distortion levels through conversions.